Your requirements could not be resolved to an installable set of packages. Problem 1 - Root composer.json requires phpunit/phpunit ^11.0.0 -> satisfiable by phpunit/phpunit[11.0.0, ..., 11.0.4]. - phpunit/phpunit[11.0.0, ..., 11.0.4] require php >=8.2 -> your php version (8.1.27) does not satisfy that requirement. Problem 2 - phpspec/prophecy-phpunit v2.2.0 requires phpunit/phpunit ^9.1 || ^10.1 || ^11.0 -> satisfiable by phpunit/phpunit[11.0.0, ..., 11.0.4]. - phpspec/prophecy-phpunit v2.1.0 requires phpunit/phpunit ^9.1 || ^10.1 -> found phpunit/phpunit[9.1.0, ..., 9.6.17, 10.1.0, ..., 10.5.11] but it conflicts with your root composer.json require (^11.0.0). - phpunit/phpunit[11.0.0, ..., 11.0.4] require php >=8.2 -> your php version (8.1.27) does not satisfy that requirement. - Root composer.json requires phpspec/prophecy-phpunit ^2.1.0 -> satisfiable by phpspec/prophecy-phpunit[v2.1.0, v2.2.0]. Use the option --with-all-dependencies (-W) to allow upgrades, downgrades and removals for packages currently locked to specific versions.